Formation tester



Oct. 26, 1943. F. w. ROLSHAUSEN ETAL 2,332,813

- FORMATION TESTER Filed Dec. 8, 1941 Patented Oct. 26, 1943 2,332,813 FORMATION TESTER Ferdinand W. Rolshausen and Saint E.

Houston, Tex., assignors to Standard velopment Company,

ware

Swain, Oil Dea corporation of Dela- Application December 8, 1941, Serial No. 422,126 4 Claims. (Cl. 2551.4)

The present invention is directed to a device for testing formations.

In the drilling of boreholes, it is often desirable to determine the productivity of various formations being penetrated by the borehole. Various arrangements have heretofore been devised for accomplishingthis end, but most; if

not all, of these known arrangements involve packing 01f a portion of a borehole and removing fluid from the packed off section.

In accordance with the present invention, a device is provided which allows samples of liquid from formations to be obtained without a packing ofi step.

Another advantage of the device of the present invention is that the means for collecting fluid samples may be forced into the formation in advance of the borehole to reach formations substantially uncontaminated by drilling fluid.

Other objects and advantages of the present invention may be seen from the following descriptiontaken' in conjunction with the drawing in which Figs. 1 and 2 taken together illustrate an embodiment of the present, invention, the

scale of Fig. 2 being smaller than that of Fig. 1, Fig. 3 is a viewof the lower end of the device taken at a right angle to the view of Fig. l, and Fig. 4 is a section taken along line IV-IV of Fig. 1.

Referring now specifically to the drawing, a tubular casing II is provided with shoulder l0, near its upper end. Above the shoulder is a locking means and release mechanism conventional ,to the art. Any suitable arrangement, such as that disclosed in U. S. Patent 2,140,097, issued December 13, 1938, may be employed. This locking means may be described briefly as including a slotted dog l2 pivoted to body H by pin 35 with spring 36 biasing the free end there of outwardly to locking position. A slidable member l3 having its upper end extending above the body and terminating in a spearhead carries pin 31 which passes through the slot in the dog.

A partition M in the upper end of casing H, and a disc l5 at its lower end defines a fluidtight chamber for receiving the sample. A check valve I6 is arranged in casing ll and is provided with a knife edge I! arranged to rest against packing ring l8 to form a seal. Spring I9 biases the knife edge against the packing ring.

A steel disc I5 is carried by a plug 20. The plug is screwed into the lower end of easing I l and is threaded to receive a bushing 2i which secures disc 15 in "place.

. Member 22 is attached by screw threads to the gated member 21. Member 27 lower end of casin ll below plug 20, and attached thereto by screws 24 extending into a circular groove cut in member 22 is wedge shaped tip 23. An elongated passage 25 extends through plug 22 and communicates to the exterior of the device by means of passages 26 which extend through members 22 and 23. Member 23 is provided with mating circular groove 32 and this, together with the method of attaching member 23, allows it to be rotated independently of member 22 while maintaining fluid communication between passage 26 and the exterior of the device. I

Bushing 2|, which acts to secure disc IS in place, .is provided with interior threads which mate with corresponding threads on an elonis provided with a point 28 directed toward the disc and arranged a short distance below it when the device is assembled for receiving a sample as shown in the drawing. The lower end of member 21 extends through the central passage of plug '22, being freely, rotatable therein, and terminates in an end of square or hexagonal section 29, fitting into a corresponding recess 30 in tip member 23. As will be seen in the drawing, the upper portion of member 27 is provided with a cavity, and

passages 3| pierce the walls of the cavity so that liquid flow may be had through passages 26 into central passage25, thence through passages 3| and into the recess immediatelybelow disc l5.

The device above described will be assembled and typically employed in the following manner: With the sample receiving cavity of the tubular member filled only with air at atmospheric pressure, disc I5 will be placed in position and sealed in place by means of bushing 2|. Elongated member 21 will then be screwed into bushing 2| with point 28 a short distance from disc l5, and plug 22 then placed in position. Thereafter, Wedge shaped tip 23 will be attached to plug member 22 by means of screws 24.

"The device assembled as above described, and as shown in the drawing, is then ready to be placed in the borehole to be sampled. The drill stem, provided with the conventional type of coring bit, will be arranged in the borehole with the bit a short distance above the bottom of the hole. The device will then be dropped down the drill stem so that shoulder l0 and dogs l2 will cooperate with the core bit and lock the device in position with its lower end extending a substantial distance below the core bit. Fig. 2 shows how the device is locked in position with respect to a fish tail bit 33. A driving lug 34, secured to the bit, is arranged to engage dog l2 drill stem will be lowered to force the tip of the device into the bottom of the borehole a desired distance. It will generally be desirable to force the tip of the device, including passages 26, into formations substantially uncontaminated by drilling fluid. After thedevice is thus in position, the drill stem will be rotated, causing the upper portion of the sampling device to rotate with respect to wedge shaped tip 23, which, is held stationary in the formation because of its shape. Rotation of the drill'stem with respect tothe tip causes elongated member 21' to move upwardly and drive point 28 through steel disc l5.

After point 28 pierces the disc, there will be a sudden rush of fluid into the chamber of the device because of the difference in pressure between the interior of the chamber and the fluid at, the bottom of the borehole. This pressure differential will drive check valve l6 upwardly and allow substantial amounts of fluid to be retained within the chamber.

After the device has remained at the bottom of the borehole a suflicient time to allow the accumulationof a sample, it may be withdrawn to the surface of the earth. This may be quickly and readily done ,by the use of a wire line and a .grappling device arranged to cooperate with spear head [3. As is well known to the art, in the operation of such grappling devices, an up- Ward pull on the wirelline is transmitted to spear head l3 which, in turn, transmits the applied force to dogs l2, unlocking them from the core barrel and releasing the sampling device, so that it may be withdrawn to the surface by means of the wire line. p

From theabove description, it will be apparent that we havehievised a simple means for obtaining fluid samples from a formation, which may be forced into the borehole a substantial distance ahead of the hole to penetrate to formations which are substantially uncontaminated by the drilling fluid. It will also be evident that the device disclosed allows-a representativefluid sample to be obtained without involving the step of packing off the borehole.

While we have disclosed a specific embodiment tance below said bit, said extension having a small area relative to the area of said bit, passages from the lower end of said, extension to a sample retaining chamber, sealing means closing the lower end of said passage, means for perforating said sealing means upon rotation of said device, and a valve arranged to prevent outward flow of fluid through the passage originally closed by said disc.

2. A wire line formation tester, comprising, in combination, an elongated casing provided with upper end of said casing to lock it in a drill bit with the lower end of the device extending a substantial distance below said bit, said lower end being of a substantially smaller area than the hole cut by said bit, a wedge-shaped tip for said device secured to the end thereof for relative rotation with respect to the remainder of said device, a passage fluidly connecting the sample receiving cavity with the exterior, said passage extending through said wedge shaped tip, a member arranged to seal said passage, a valve arranged to allow fluid flow through said passage into the chamber and to prevent fluid flow from said chamber, and a means operated by-relative rotation between said tip and the remainder of the sampling device for piercing said sealing member.

3. A wire line formation tester comprising in combination an elongated casing defining a cavity in the lower portion thereof with a threaded passage extending from said cavity to the exterior of the casing, means secured to the upper end of said casing adapted to releasably lock said end in a drill bit with the lower end extending a substantial distance below said bit, a wedge shaped tip secured to the lower end of said casing for rotary movement with respect to said casing, with the interior of said tip defining an irregularly shaped longitudinally extending cavity, a one-way valve arranged in the passage actuated by the pressure of fluid to permit the flow of fluid into the chamber and to prevent the discharge of fluid therefrom, a frangible closure closing said passage, and an elongated member having one end provided with a point and screw threads and the other with an irregularly shaped head corresponding to the shape of the passage of said tip arranged in the passage with said head in the tip, the screw threads of the elongated member engaging said threads in the pas- .sage of said casing whereby relative rotation between said member and said tip causes said tip to puncture the frangible member.

4. An assembly comprising in combination a drill bit provided with a central passage, an elongated casing with its lower portion defining a cavity and a downwardly extending threaded .50 of the present invention, it-will be understood drill stem with respect to the lower end of said 1 a sample receiving cavity, means arranged at the passage connecting said cavity with the exterior of the device, said casing extending downwardly through the central passage of the bit with its lower portion a substantial distance below said bit, a'locking means secured to the upper end of said casing releasably locking said casing to said drill bit, awedge shaped tip provided with a central interior passage of irregular cross section swivelly connected to the lower end of said casing, a one-way valve arranged in said casing to allow the entrance of said fluid in said passage and to prevent its discharge from said chamber, a frangible closure sealing said passage,- an elongated member having one endprovided with a point and screw threads arranged in said passage with said pbint adjacent said frangible member and its threads engaging the threads of the passage, an irregularly shaped head secured to the other end of said member and arranged in the irregularly shaped passage of said tip whereby rotation of said tip forces said point against the fran ible member.

FERDINAND W. ROLSHAUSEN. SAINT E. SWAIN. 

